Symptoms

Confluence 3.5 or 4.0 fails to start up. The following appears in the atlassian-confluence.log:

Another example:

Cause

The format of the web.xml file included with Confluence has changed in 3.5 or 4.0. This error most commonly occurs when copying a web.xml file from an older version of Confluence or making manual changes.

Resolution

Revert to the web.xml file included with the Confluence installation. If you have customizations, you will need to make them to the Confluence web.xml file.